Can screen layouts or workspaces be locked?
Blender uses different layout screens or workspaces, all of them customizable.
While there are a number of built-in presets, those might not fit your workflow. So create different ones depending on your needs and get into the habit of using keyboard shortcuts to switch between them instead of resizing/splitting/changing modes and making a mess of the interface.
For 2.79 the shortcuts are:
CtrlLeft and CtrlRight Arrow
In 2.8 use:
CtrlPage Up and CtrlPage Down
Or use the menu:


To make your custom layout screens permanent:
Start blender.
On blender 2.79
Make new layout screens by pressing on the + sign:

Name them as something that make sense to you and re-arrange the windows to suit your needs.

Now save all of this as your startup file using CtrlU.
For 2.8
Create a new workspace by clicking on the plus sign next to the existing workspaces and select Duplicate Current.

You can rename the workspace by double clicking on the tab and typing a name that makes sense to you.

Arrange the workspace to fit your needs, then save the current project as the startup file.

From then on, every time you open blender your custom layouts will be loaded.
Alternatively, if you don't want to make permanent layout screens, just create a duplicate of your default layout and work on that one. That way you can go back to the original when you need.
If you moved things around and don't have a default layout screen to go back to, you can save your file, quit blender and re-open it making sure you don't load the User Interface (un-check the Load UI box). The file will then open using the default startup file's layout.